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US5035813A Expired / Lapsed US ⏱️ 0.0 years remaining

Process and composition for treating underground formations penetrated by a well borehole

Assignee: Union Oil Company of California
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Filing: 1988-12-30
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Granted: 1991-07-30
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Expires: 2008-12-30
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Abstract

Abstract An aqueous fluid for treating underground, carbon dioxide-containing formations penetrated by casing regions of a wellbore, prior to the cementing of casings into the wellbore, comprises: (i) water, (ii) an agent which substantially increases (preferably by at least about 50 percent) the solubility of lime in water, and (iii) lime in an amount at least about saturating the water in the fluid. The lime in the treatment fluid reacts with carbon dioxide in penetrated formations to produce insoluble calcium carbonate, which blocks pores in the formations. Insoluble calcium hydroxide, formed by reaction of the lime with the water in the treatment fluid, deposits as an insoluble filter cake on the walls of the borehole where the fluid penetrates formations. The calcium hydroxide filter cake may react with the carbon dioxide to form additional calcium carbonate which helps the filter cake form a tight, impermeable barrier at the borehole. The formation is thus sealed at the borehole and the escape of pressurized fluids from penetrated formations into the borehole is prevented, thereby preventing gas-caused wormholes in the casing cement. If pressurized formations penetrated by the borehole do not contain carbon dioxide, injection of the treatment fluid is preceded by the injection of an aqueous solution containing carbon dioxide or a carbon dioxide precursor, thereby providing the carbon dioxide needed for the formation of the calcium hydroxide and calcium carbonate for sealing off the formations. Corresponding processes are provided for cementing casings into wellbores and for reducing fluid leakage through or past existing casing installations.

Inventors

  • 👤 Jian-Chyun Shen

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 21:07
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/42; E; E21; E21B; E21B33/00; E21B33/10; E21B33/13; E21B33/14; Y; Y10; Y10S; Y10S507/00; Y10S507/925

Claims Analysis

Total Claims: 38
Claim 1
Independent Claim 119 words
An aqueous fluid for treating an underground formation penetrated by a well borehole, the fluid comprising: (a) water; (b) lime in amount of between 10 and about 30 percent by weight of the total amount of water in the fluid; (c) glycerol in an amount of between about 5 and about 50 percent by weight of the total amount of water in the fluid; and (d) sugar in the amount of between about 1 and about 20 percent by weight of the total amount of water in the fluid, wherein the combined amount of glycerol and sugar in the fluid is between about 6 and about 50 percent by weight of the total amount of water in the fluid.
Claim 2
Dependent Claim 119 words
An aqueous fluid for treating an underground formation penetrated by a well borehole, the fluid comprising: (a) water; (b) lime in amount of between 10 and about 30 percent by weight of the total amount of water in the fluid; (c) glycerol in an amount of between about 5 and about 50 percent by weight of the total amount of water in the fluid; and (d) sugar in the amount of between about 1 and about 20 percent by weight of the total amount of water in the fluid, wherein the combined amount of glycerol and sugar in the fluid is between about 6 and about 50 percent by weight of the total amount of water in the fluid.
Claim 3
Dependent Claim 32 words
The treatment fluid as claimed in claim 1, wherein the amount of lime is between about 10 and about 20 percent by weight of the total amount of water in the fluid.
Claim 4
Dependent Claim 34 words
The treatment fluid as claimed in claim 1, wherein the amount of glycerol in the fluid is between about 10 and 20 percent by weight of the total amount of water in the fluid.
Claim 5
Dependent Claim 40 words
The treatment fluid as claimed in claim 1, wherein the fluid additionally comprises a silica flour weighting agent in an amount of between about 1 and about 20 percent by weight of the total amount of water in the fluid.
Claim 6
Dependent Claim 23 words
The treatment fluid as claimed in claim 1, wherein the fluid has a viscosity, at 20° C., no greater than about 10 centipoises.
Claim 7
Dependent Claim 159 words
An aqueous fluid for treating an underground formation penetrated by a well borehole, the fluid having a viscosity of no more than 10 centipoise at 20° C. and comprising: (a) water; (b) lime in amount of between about 10 and about 20 percent by weight of the total amount of water in the fluid; (c) glycerol in an amount of between about 10 and about 20 percent by weight of the total amount of water in the fluid; (d) sugar in the amount of between about 1 and about 20 percent by weight of the total amount of water in the fluid, wherein the combined amount of glycerol and sugar in the fluid is between about 6 and about 50 percent by weight of the total amount of water in the fluid; and (e) a weighting agent in an amount of between about 5 and about 50 percent by weight of the total amount of water in the fluid.
Claim 8
Dependent Claim 159 words
An aqueous fluid for treating an underground formation penetrated by a well borehole, the fluid having a viscosity of no more than 10 centipoise at 20° C. and comprising: (a) water; (b) lime in amount of between about 10 and about 20 percent by weight of the total amount of water in the fluid; (c) glycerol in an amount of between about 10 and about 20 percent by weight of the total amount of water in the fluid; (d) sugar in the amount of between about 1 and about 20 percent by weight of the total amount of water in the fluid, wherein the combined amount of glycerol and sugar in the fluid is between about 6 and about 50 percent by weight of the total amount of water in the fluid; and (e) a weighting agent in an amount of between about 5 and about 50 percent by weight of the total amount of water in the fluid.
Claim 9
Dependent Claim 16 words
A carbon dioxide injection fluid comprising: (a) water; (b) carbon dioxide; and (c) a weighting agent.
Claim 10
Dependent Claim 16 words
A carbon dioxide injection fluid comprising: (a) water; (b) carbon dioxide; and (c) a weighting agent.
Claim 11
Dependent Claim 19 words
The injection fluid of claim 7 wherein sufficient carbon dioxide is present in the fluid to saturate the water.
Claim 12
Dependent Claim 26 words
The injection fluid of claim 7 wherein the weighting agent is present in an amount of about 5 to about 50 weight percent of the water.
Claim 13
Dependent Claim 10 words
The injection fluid of claim 7 further comprising a dispersant.
Claim 14
Dependent Claim 21 words
The injection fluid of claim 10 wherein the dispersant is selected from the group consisting of synthetic polymers and lignin derivatives.
Claim 15
Dependent Claim 25 words
The injection fluid of claim 10 wherein the dispersant is present in a concentration of about 0.1 to about 1 weight percent of the water.
Claim 16
Dependent Claim 58 words
The injection fluid of claim 7 further comprising a dispersant in a concentration of about 0.1 to about 1 weight percent of the water, and wherein sufficient carbon dioxide is present in the fluid to saturate the water and the weighting agent is present in an amount of about 5 to about 50 weight present of the water.
Claim 17
Dependent Claim 28 words
An aqueous fluid for treating an underground formation penetrated by a well borehole, the fluid consisting of: (a) water; (b) lime; (c) glycerol; and (d) a weighting agent.
Claim 18
Dependent Claim 28 words
An aqueous fluid for treating an underground formation penetrated by a well borehole, the fluid consisting of: (a) water; (b) lime; (c) glycerol; and (d) a weighting agent.
Claim 19
Dependent Claim 26 words
The treatment fluid of claim 14 wherein the glycerol is present in the treatment fluid in a concentration of about 5 to about 50 weight percent.
Claim 20
Dependent Claim 25 words
The treatment fluid of claim 14 wherein the lime is present in the treatment fluid in a concentration of 10 to about 30 weight percent.
Claim 21
Dependent Claim 25 words
The treatment fluid of claim 14 wherein the lime is present in the treatment fluid in a concentration of 10 to about 20 weight percent.
Claim 22
Dependent Claim 45 words
The treatment fluid of claim 14 wherein the glycerol is present in the treatment fluid in a concentration of about 5 to about 50 weight percent, and the lime is present in the treatment fluid in a concentration of 10 to about 30 weight percent.
Claim 23
Dependent Claim 45 words
The treatment fluid of claim 14 wherein the glycerol is present in the treatment fluid in a concentration of about 10 to about 20 weight percent, and the lime is present in the treatment fluid in a concentration of 10 to about 20 weight percent.
Claim 24
Dependent Claim 25 words
The treatment fluid of claim 14 wherein the weighting agent is present in the treatment fluid in a concentration up to about 50 weight percent.
Claim 25
Dependent Claim 30 words
An aqueous fluid for treating an underground formation penetrated by a well borehole, the fluid consisting of: (a) water; (b) lime; (c) glycerol; (d) sugar; and (e) a weighting agent.
Claim 26
Dependent Claim 30 words
An aqueous fluid for treating an underground formation penetrated by a well borehole, the fluid consisting of: (a) water; (b) lime; (c) glycerol; (d) sugar; and (e) a weighting agent.
Claim 27
Dependent Claim 26 words
The treatment fluid of claim 21 wherein the glycerol is present in the treatment fluid in a concentration of about 5 to about 50 weight percent.
Claim 28
Dependent Claim 26 words
The treatment fluid of claim 21 wherein the sugar is present in the treatment fluid in a concentration of about 1 to about 20 weight percent.
Claim 29
Dependent Claim 46 words
The treatment fluid of claim 21 wherein the glycerol is present in the treatment fluid in a concentration of about 5 to about 50 weight percent, and the sugar is present in the treatment fluid in a concentration of about 1 to about 20 weight percent.
Claim 30
Dependent Claim 26 words
The treatment fluid of claim 24 wherein the combined concentrations of glycerol and sugar in the treatment fluid is about 6 to about 50 weight percent.
Claim 31
Dependent Claim 25 words
The treatment fluid of claim 21 wherein the lime is present in the treatment fluid in a concentration of 10 to about 30 weight percent.
Claim 32
Dependent Claim 25 words
The treatment fluid of claim 21 wherein the lime is present in the treatment fluid in a concentration of 10 to about 20 weight percent.
Claim 33
Dependent Claim 45 words
The treatment fluid of claim 21 wherein the glycerol is present in the treatment fluid in a concentration of about 5 to about 50 weight percent, and the lime is present in the treatment fluid in a concentration of 10 to about 30 weight percent.
Claim 34
Dependent Claim 26 words
The treatment fluid of claim 28 wherein the sugar is present in the treatment fluid in a concentration of about 1 to about 20 weight percent.
Claim 35
Dependent Claim 26 words
The treatment fluid of claim 29 wherein the combined concentrations of glycerol and sugar in the treatment fluid is about 6 to about 50 weight percent.
Claim 36
Dependent Claim 45 words
The treatment fluid of claim 21 wherein the glycerol is present in the treatment fluid in a concentration of about 10 to about 20 weight percent, and the lime is present in the treatment fluid in a concentration of 10 to about 20 weight percent.
Claim 37
Dependent Claim 26 words
The treatment fluid of claim 31 wherein the sugar is present in the treatment fluid in a concentration of about 1 to about 20 weight percent.
Claim 38
Dependent Claim 25 words
The treatment fluid of claim 21 wherein the weighting agent is present in the treatment fluid in a concentration up to about 50 weight percent.

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Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-07-29 1995-01-28 1995-07-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-07-29 1999-01-28 1999-07-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-07-29 2003-01-28 2003-07-30 $7700.00 Window Closed / Lapsed

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